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Chiarini Franco - One of the best experts on this subject based on the ideXlab platform.

Knapp Sandra - One of the best experts on this subject based on the ideXlab platform.

Rex Stanton - One of the best experts on this subject based on the ideXlab platform.

  • herbicidal control of Solanum elaeagnifolium cav in australia
    Crop Protection, 2016
    Co-Authors: Rex Stanton, Deirdre Lemerle
    Abstract:

    Abstract Solanum elaeagnifolium Cav. is considered as one of the worst weeds of crop and pasture systems in temperate Australia. Effective long-term control is difficult due to the extensive root system. Field experiments were conducted at two locations in south-eastern Australia between 2006 and 2008 to examine a range of herbicides for control of S. elaeagnifolium on seed production and root regrowth. Herbicide performance was affected by herbicide, weed growth stage and environmental factors. Pyridine herbicides, such as pre-packed mixtures of aminopyralid + fluroxypyr and triclopyr + picloram + aminopyralid were the most effective and consistently reduced within-season aerial growth by 60–90% in both seasons. Overall control using glyphosate-based treatments was generally reduced due to emergence of new stems following herbicide application. Three picloram-based treatments provided the best and most consistent long-term control on root regrowth after two seasons, reducing stem emergence by 45–88%, especially with a late application of herbicides. The efficacy of residual herbicides such as atrazine or imazapic + imazapyr depends on rainfall conditions. Seedset control was best achieved with herbicides applied at the start of flowering stage, with no viable seed produced following treatments of 2,4-D amine + picloram and triclopyr + picloram + aminopyralid. These two treatments also significantly reduced viable seed production when applied at the early berry stage. The results indicate that an application at early flowering followed by a late application in autumn is necessary to effectively control the seedset (seedbank) and the root regrowth (rootbank) of S. elaeagnifolium .

  • intrusive trichome bases in the leaves of silverleaf nightshade Solanum elaeagnifolium solanaceae do not facilitate fluorescent tracer uptake
    American Journal of Botany, 2013
    Co-Authors: Geoffrey E Burrows, Xiaocheng Zhu, Rex Stanton, Rosemary G White, John D I Harper, Roger Heady, Deirdre Lemerle
    Abstract:

     Premise of the study: Solanum elaeagnifolium (silverleaf nightshade), having originated in the Americas, is now a serious summer-growing, perennial weed in many countries, including Australia. Most surfaces of the plants have a dense covering of trichomes, giving them a silvery-white appearance, hence the common name. We aimed to identify structural and functional properties of its leaves, especially the trichomes, that may affect the uptake of foliar-applied tracer dyes.  Methods: The structure of leaves of Solanum elaeagnifolium was examined by light and scanning electron microscopy. The potential for transport of materials between trichomes and veins was studied with symplastic (carboxyfl uorescein diacetate) and apoplastic (lucifer yellow) tracer dyes.  Key results: Mature leaves had a dense covering of complex, stellate trichomes on both surfaces, particularly the abaxial. The basal cells of Solanum elaeagnifolium trichomes penetrated into the underlying palisade mesophyll layers. The innermost lobes of these basal cells sometimes contacted the bundle sheath of the veins, but were not observed to directly contact the xylem or phloem. We found that neither symplastic nor apoplastic dyes were transferred between the basal cells of the trichomes and the vascular tissues. The trichome layer repelled water-based tracer dyes, while one of four adjuvants tested facilitated entry of both symplastic and apoplastic dyes.  Conclusions: Our results did not support a transport function for the trichomes. The trichomes may protect the mesophytic leaves from invertebrate herbivory, while also probably decreasing radiation absorbed resulting in cooler leaves in this summergrowing species.

  • morphological variation of Solanum elaeagnifolium in south eastern australia
    Weed Research, 2013
    Co-Authors: Xiaocheng Zhu, Deirdre Lemerle, Rex Stanton, Geoffrey E Burrows, Harsh Raman
    Abstract:

    Summary Solanum elaeagnifolium (silverleaf nightshade) is an invasive perennial weed in Australia, with aerial growth commencing in spring from either the perennial root system or the soil seedbank, with senescence occurring in autumn. A total of 642 S. elaeagnifolium individuals were collected at flowering from 92 locations in south-eastern Australia to study morphological variation and its implications for management. Large morphological variation was found between individuals from different locations. Leaf length, width and area ranged from 1.44 to 10.6 cm, 0.39 to 4.09 cm and 0.41 to 25.8 cm2 respectively. Plants from higher rainfall regions were significantly taller and had larger leaves, suggesting a possible correlation between rainfall and morphology. Scanning electron microscopy comparison of leaf surfaces showed lower trichome and stomatal densities on the adaxial surface (67.0 ± 3.3 trichomes mm−2 and 603.4 ± 29.2 stomata mm−2 respectively) than on the abaxial surface (131.9 ± 7.2 trichomes mm−2 and 813.7 ± 30.5 stomata mm−2 respectively). The morphological plasticity of S. elaeagnifolium highlighted in this study could probably contribute to its adaptability and partly explain its establishment and continuing expansion in Australia.

  • genetic variation and structure of Solanum elaeagnifolium in australia analysed by amplified fragment length polymorphism markers
    Weed Research, 2013
    Co-Authors: Xiaocheng Zhu, Harsh Raman, Deirdre Lemerle, Rex Stanton, Geoffrey E Burrows
    Abstract:

    Summary Solanum elaeagnifolium is a weed of national significance in Australia. However, the genetic diversity of S. elaeagnifolium is poorly understood. Four amplified fragment length polymorphism primer combinations were utilised to investigate the genetic variation and structure of 187 S. elaeagnifolium individuals collected from 94 locations in Australia. High genetic diversity was found, with an average Jaccard's genetic similarity at 0.26. Individuals were assigned to two genetic clusters or considered as admixed according to their membership coefficient value (q) calculated by Bayesian model-based genetic structure analysis. This suggested that Australian S. elaeagnifolium may have originated from two distinct gene pools. These results were further supported by principal co-ordinates analysis. Large spatial groups of individuals assigning to these two gene pools were found in western Victoria and south-western New South Wales (NSW) and northern NSW, which correlated well with the early records of S. elaeagnifolium in both regions. The high genetic diversity found here could add difficulties to effective control of S. elaeagnifolium across regions.

  • genetic variation in Solanum elaeagnifolium in australia using ssr markers
    Plant protection quarterly, 2013
    Co-Authors: Xiaocheng Zhu, Harsh Raman, Deirdre Lemerle, Rex Stanton, Geoffrey E Burrows
    Abstract:

    Silverleaf nightshade (Solanum elaeagnifolium Cav.) is a problematic summergrowing perennial weed in Australia. The genetic diversity of silverleaf nightshade is poorly understood. Nine silverleaf nightshade specific and 10 cross-species simple sequence repeat (SSR) primer pairs were utilised to investigate the genetic variations among 94 silverleaf nightshade populations collected in Australia. High genetic diversity was found within silverleaf nightshade populations, with an average genetic similarity of 0.43. The Unweighted Pair Group Method with Arithmetic mean based dendrogram indicated the presence of genetically diverse silverleaf nightshade populations in Australia. However, no well supported genetic structure was found. The Mantel test indicated that there is no significant correlation between genetic variation and geographic distance. These results suggested a lack of geographic structure in genetic diversity, which is probably due to the long distance spread of seeds of silverleaf nightshade. The high genetic diversity of silverleaf nightshade could contribute to the inconsistency in control efficacy between populations.

M Bouhache - One of the best experts on this subject based on the ideXlab platform.

  • variation intraspecifique du potentiel invasif de la morelle jaune Solanum elaeagnifolium cav au maroc influence des conditions ecologiques
    Revue Marocaine de Protection des Plantes, 2020
    Co-Authors: Ben S Ghabrit, M Bouhache, A Birouk, C Bon
    Abstract:

    Le potentiel invasif ( PI ) de Solanum elaeagnifolium Cav. (SOLEL) au Maroc et les conditions ecologiques qui le favoriseraient ne sont pas connus. L’objectif de cette etude a ete donc d’evaluer la variabilite du PI et sa structuration et identifier les conditions ecologiques favorisant la classe de PI la plus invasive. Pour ce faire, le PI de 188 populations representatives de differentes conditions ecologiques presentes au Maroc a ete determine par l’analyse de traits d’histoire de vie de SOLEL lies a la reproduction sexuee. L’analyse de la variabilite du P i et de sa structuration par Classification Ascendant Hierarchique (CAH) et Analyse Discriminante Lineaire (ADL) a permis d’etablir des classes de PI . L’influence des conditions ecologiques sur la distribution de ces classes de PI a ete evaluee.  L’analyse des 11 variables choisies a montre une grande variabilite phenotypique de SOLEL. L’analyse par regroupement a mis en evidence quatre groupes distincts de PI .  Pour chacune des six variables liees au PI , la comparaison des moyennes de ces groupes a defini quatre classes de PI , la classe la plus invasive ayant le plus grand nombre de moyennes les plus elevees. L’etude de l’influence des conditions ecologiques sur la distribution des classes de PI a montre que les conditions climatiques et d’altitude les plus severes favoriseraient la classe la plus invasive.

  • Solanum elaeagnifolium cav une menace a l agriculture et a l environnement dans la region mediterraneenne
    Revue Marocaine de Protection des Plantes, 2014
    Co-Authors: M Bouhache
    Abstract:

    Native to tropical America (Argentina, north-east Mexico and south–west USA), Solanum elaeagnifolium Cavanilles (Silverleaf nightshade) is a deep rooted perennial broadleaved trans continents weed. It is propagated by seed and/or vegetative fragments of the all plant organs. It was reported as a weed or /and a colonizing invader species in many countries in Africa; Europe; Americas; Asia and Oceania. S. elaeagnifolium was introduced to these countries as seeds or vegetative fragments by contaminated seeds, fodder, ballast and bedding used in animal transport. The rapid dissemination of this species may be explained by its high vegetative regeneration capacity, high seed production per plant and diversification and efficacy of spreading means and ways. Since S. elaeagnifolium is officially declared as a noxious weed, a control strategy programme should be established on the basis of prevention and control. The prevention includes legislation or regulatory aspects, avoidance of spread means and extermination of isolated plants and small patches as they appear. Cultural, mechanical, chemical and biological control methods may be used separately or combined in an integrated way to keep this weed under control.

  • etat actuel de l infestation par la morelle jaune Solanum elaeagnifolium cav au maroc
    Eppo Bulletin, 2007
    Co-Authors: A Taleb, M Bouhache, A Ameur, Y Baye
    Abstract:

    Signalee pour la premiere fois au Maroc en 1949, la morelle jaune (Solanum elaeagnifolium Cav.) est devenue a partir des annees 80 une adventice preoccupante a l’echelle nationale. Dans un premier temps, l’infestation est restee limitee a la region du Tadla. Mais vingt ans ont suffi a la morelle jaune pour sortir de son berceau et se propager vers des regions eloignees. Des etudes et des enquetes effectuees au Maroc ont permis de souligner la grande diversite et l’efficacite de facteurs de dissemination tels que: le fumier organique, les ovins, l’eau d’irrigation, les machines agricoles, les plants en motte et le vent. Toutefois, les trois premiers facteurs restent les plus importants. Suivant les conditions locales, certains de ces facteurs de dissemination deviennent preponderants et peuvent etre simultanes ou successifs.

  • strategie de lutte chimique contre la morelle jaune Solanum elaeagnifolium cav au maroc
    Eppo Bulletin, 2007
    Co-Authors: Y Baye, A Ameur, M Bouhache, A Taleb
    Abstract:

    La lutte chimique contre Solanum elaeagnifolium Cav. a fait l’objet de nombreux travaux de recherche, et ce grâce aux nombreuses experimentations menees sur un grand nombre d’herbicides (doses, stades d’application, conditions climatiques, biotopes traites, etc.). Les resultats montrent que les herbicides appliques en cours de vegetation n’aboutissent generallement pas a un bon controle de l’adventice. En effet, les doses d’herbicides selectifs de ces cultures sont peu efficaces contre S. elaeagnifolium. Le glyphosate, le sulfosate et l’aminotriazole – herbicides systemiques – se sont montres tres performants et sont preconises principalement pour le traitement non selectif des vergers d’oliviers, d’agrumes et d’arbres fruitiers ainsi que des parcelles en postrecolte des cultures (cereales, betterave a sucre, maraichage). Ils necessitent des conditions d’application particulieres et sont conseilles surtout en cas de fortes infestations. Les phytohormones, l’imazapyr et le bromacile sont utilises pour le desherbage des bordures de routes publiques boisees et/ou non boisees et eventuellement les parcelles non exploitees. Le bromacile peut etre utilise dans les vergers d’agrumes ages de plus de 4 ans, mais uniquement sur des zones fortement infestees compte tenu de son cout eleve. Par le biais du transfert de technologie chez les agriculteurs, ces derniers ont ete convaincus de la possibilite de controler cette adventice par le glyphosate et d’autres herbicides lorsqu’un certain nombre de conditions sont respectees. En se basant sur ces resultats, des operations de lutte chimique ont ete menees a grande echelle par les organismes de developpement.

  • etude de la competition entre la morelle jaune Solanum elaeagnifolium cav et le mais de printemps zea mays l
    Eppo Bulletin, 2007
    Co-Authors: Y Baye, M Bouhache
    Abstract:

    La competition entre la morelle jaune (Solanum elaeagnifolium Cav.) et le mais (Zea mays L.) a ete etudiee au champ au cours de la saison 2001. Des durees de competition avec la morelle jaune plus ou moins longues, tardives et precoces ont ete imposees a la culture au cours du cycle. Les resultats montrent que les parametres de croissance (hauteur, surface foliaire, matiere seche) du mais ont ete affectes par la presence de la mauvaise herbe. Plus la duree de competition est longue, plus ces parametres sont reduits. Les principales composantes du rendement, a savoir le nombre de grains/epi et le poids de 1000 grains ont ete fortement influencees par la morelle jaune. Il en est de meme pour le rendement global qui diminue d'autant plus que la competition avec l'adventice dure longtemps. Ce dernier a ete reduit de 64% en cas de non desherbage. Pour des pertes de rendements tolerees de 15%. la periode critique de sensibilite a la mauvaise herbe serait situee entre le stade floraison de la culture et le stade grain laiteux avance. La mauvaise herbe arrive a accomplir parfaitement son cycle biologique lorsque aucun desherbage n'est effectue. Des desherbages se poursuivant jusqu'au stade grain pâteux de la culture ont permis de reduire la production de fruits de la mauvaise herbe.

Sagona Eva - One of the best experts on this subject based on the ideXlab platform.